Compounds with a cephalosporin nucleus belong to a well-known family of antibiotics that have been widely used in recent years for the treatment of various infectious diseases. A number of commercially useful cephalosporin antibiotics have been obtained by varying the substitution at the 3-position of the cephalosporin nucleus and by various modifications of the side-chain substituents at the 7-position of the cephalosporin nucleus. The search continues, however, for new compounds which possess a broad spectrum of antibacterial activity and which possess a high degree of activity toward both gram-positive and gram-negative bacteria without causing undesirable contraindications when administered to humans.
In an effort to improve upon the antibacterial properties of existing compounds, efforts have been directed towards the introduction of a 1,3-dithiolan ring directly at the 7-position of the cephalosporin nucleus. More particularly, the preparation of such cephalosporanic acid derivatives having in addition an acyl or alkyl derivative in the 4-position and a shift of unsaturation to the .DELTA..sup.2 -position of the cephalosporin nucleus provides a novel class of cephalosporin derivatives that are effective against one or more gram-positive and gram-negative microorganisms. Accordingly, the compounds of the present invention are effective in the treatment of various infectious diseases caused by such gram-positive and gram-negative bacteria in poultry or in mammals including man. The compounds herein disclosed are suitable for use in certain topical germicidal preparations or as surface disinfectants.